Circuit continuing device



Dec. 12, 1933. DOUGLAS 1,939,295

CIRCUIT CONTINUING DEVICE Filed Feb. 27, 1951 WIIIIIIIIaI/d I5 alga? Patented Dec. 12, 1933 UNITED STATES PATENT OFFICE 7 Claims.

My invention relates to circuit continuing devices and is of particular service in connection with dash lamps for automobiles in which the circuit continuing devices include an incandescent light bulb.

Among other objects, my invention aims to provide an improved dash lamp which is simple in construction and efficient in operation.

The invention may be understood from the illustrative embodiment thereof shown in the accompanying drawing, in which-- Figure 1 is an axial section, showing some of the parts in elevation, of a circuit continuing device embodying my invention;

Figure 2 is a view similar to Figure 1 but rotated ninety degrees and showing more of the parts in elevation;

Figure 3 is a sectional view taken on the line 3-3 of Figure 1;

Figure 4 is a sectional view taken on the line 44 of Figure 1;

Figure 5 is a view taken on the line 55 of Figure 1 and showing parts in side elevation and another part in section; and

Figure 6 is a rear end view taken on the line 6-6 of Figure 1.

Referring to the figures of the drawing, I have shown a circuit continuing device such as a dash lamp which may include a cylindrical metallic shell 1, having the integral lugs 2 and 3 adapted to engage and rigidly clamp the shell to a suitable support upon the dashboard such as a bracket, a portion of which is indicated at 4.

The shell 1 houses a metallic core 5 which is adapted to have rotative and longitudinal movement with respect to the bore of the shell as presently described. The core 5 is shown provided with a skirt portion 6 and, at its forward end, is axially recessed by reason of being provided with the hollow conical portion 7, which is apertured at its inner end concentrically with the core. The skirt portion 6 is in close proximity to the surface of the bore of the shell. The core 5 is provided with a tubular portion 8 which is coaxial with the core and isrigidly connected to the core at the inner end of the recessed portion 7, for example by being crimped about the margin of the aperture in the recess of the core as at 9. The tubular portion 8 loosely mounts a thin metallic washer 10 which is adapted to support the tubular portion 8 in the shell but to permit rotative and longitudinal movement or the tube with respect to the shell and washer. The washer 10 is maintained in position in the shell 1 by the pressure of a coiled spring 11, which presses the washer 10 against an abutment such as the ears 12 formed with the shell 1 and bent to lap the washer 10, the washer 10 and the cars 11 thus together forming an abutment in the bore of the shell for the spring 11. The coil spring 11, which bears also against the conical back of the axially recessed portion 7 of the core 5, simultaneously presses the core 5 and its tubular portion 8 longitudinally of the shell 1 forwardly and in a direction tending to separate the core 5 and the washer 10, movement in this direction being limited by a flange 13 at the opposite or, rear end of the tubular portion 8.

A current carrying member is provided in the shell 1, which member is here represented by an insulated wire 14, which is passed loosely through the tubular portion 8 and as here shown I has its terminus soldered in a cup-shaped metallic contact member 15, which is concentrically carried by an insulating washer 16, which, in turn is concentrically carried by the recessed portion 7 of the core 5. The contact member 15 is thus substantially coaxial with the shell 1. The insulating washer 16 is of a diameter approximating the maximum diameter of the recessed or conical portion 7. The washer 16 is revolubly held in the axially recessed portion 7 of the core 5, as by means of fingers 17 struck from the core and turned to hook loosely over the edge of the insulating washer 16. The insulation of the wire 14 is continuous substantially up to the washer 16. So constructed and arranged, the wire 14, together with the contact 15 and the washer 16,

are free to rotate relatively to the core 5 and tubular portion 8, and the core 5, in turn, is free to rotate relatively to the shell 1.

A contact carrying plug represented by an incandescent light bulb 18 having a base 19 has bayonet projection and bayonet channel connection with the shell 1, a snug fit of the base 19 with the shell being assured by a spring tongue 20 which is struck from the body of the shell 1 and extends into the bore of the shell. The bayonet pins 21 are thus frictionally maintained in their seats 22. The base 19 is provided with a contact 23 which is coaxial therewith and which in one of the alternative longitudinal positions of the core 5, engages the contact 15 to close the circuit. Such a position of the complemetary ward movement as determined by the flange 13 on the tubular portion. The cup-shaped contact 15 provides a seat for the contact 23 which desirably tends to grip the contact 23 and prevent flickering of the light due to vibration of the parts. To enhance this gripping effect, the periphery of the cup-shaped contact member 15 is desirably roughened slightly as at 24 to increase the friction between it and the softer contact 23.

When it is desired to open the circuit; the core 5 may be moved longitudinally in the shell 1 away from the base 19, thus separating the contacts 15 and 23. I have provided means for effecting longitudinal movement of the core 5 which means is here shown as inclusive of a handle 25. This handle may be locked to the core as by having a reduced portion 26 of the handle passed through a slot 2'7 in the skirt 6 of the core. The slot 27 desirably terminates in a wide mouth 28 so that the handle can be removed by appropriate manipulation of the parts. The handle 25 extends outwardly from the core 5 through a cam slot here shown as the oblique.

slot 29 in the shell 1. By moving the handle in this slot the core may be rotated, and simultaneously with said rotation, either retracted or advanced in the shell to open or close the circuit as desired. A seat 30 for the handle 25 in the slot 29 permits the core to be held in a retracted position and the circuit maintained open. The handle 25, having no grooved connection with the margins of the slot 29, has no tendency to stick in the slot but moves freely therein. It is highly desirable that the wire 14 be not rotated by the rotation of the core 5, and by a construc-' tion such as I have herein exemplified, the wire 14 with its terminal contact 15 is free to turn relatively to the core when the latter is being rotated during the opening or closing of the circuit, the wire turning freely in the tubular portion 8 and the contact member 15 turning freely in the recessed portion of the core. The wire 14 as here shown is provided with a metallic armor 31 and the armor is desirably continued well into the tubular portion 8 so that friction is prevented between the tube and the insulation of the wire which would tend to fray the insulation.

The circuit continuing device here shown for illustration being in the form of a dash lamp, I have shown a cowl 32 over the bulb 18 which directs the light from the bulb 18, by reason of an opening 33 in the cowl, upon an instrument board of an automobile, for example. The cowl 32 ishere shown cylindrical and is arranged to slip snugly over the shell 1 and is held upon the shell by spring action of the shell. In this instance, the shell 1 has its wall split longitudinally as at 34 continuing the bayonet channel 34a and leaving a free segmental portion 35 of the shell which acts as a spring to provide a snug fit between the shell and cowl. The portion of the shell upon which the cowl seats includes a flange 36 which is bent back upon the exterior of the shell and provides an annular bearing 37 for the cowl. The flange 36 may be extended longitudinally of the shell as by the spring fingers 38 which have their bases slightly depressed below the bearing 37 and are desirably tapered in cross section to increase their resiliency and which cooperate with the bearing 37 and the free segmental portion 35 of the shell to maintain the cowl securely upon the shell against tine action, for example, of even severe vibration. So constructed and arranged, the function of the spring fingers 38 is substantially that of a spring and not of a bearing, and they desirably do not have tendency to force the cowl away from the shell. An internal rib 39 on the cowl limits the extent of its engagement with the flange 36.

The metallic washer 10 is also desirably provided with the peripheral spring fingers 40 which engage the wall of the bore of the shell 1 and space the body of the washer from said wall to permit the washer to accommodate itself to the expansion and contraction of the shell 1 as already explained.

It will be understood that the circuit here shown for purposes of illustration is a so-called single pole circuit in which the bulb 18 may be grounded through a metallic sheath surrounding the base 19 and the metal of the parts.

Obviously, the invention is not limited to the particular details of construction here shown. Furthermore, it is not indispensable that all features of the invention be employed conjointly, as they may be advantageously used in various combinations and sub-combinations.

I claim:

1. In a circuit continuing device, the combination with a metallic shell formed at its forward end to receive a contact carrying plug and having an abutment at its other end; of a core having a skirt portion in close proximity to the surface of the bore of the shell and having a tubular portion extending rearwardly of the shell, said core having an axially recessed portion at its forward end; an insulated wire passing through said tubularportion and secured in a cup-shaped contact member, said contact member being carried by an insulating washer disposed in said axially recessed portion of the core and being coaxial with said core and said washer, the insulation of said wire being continued substantially to said insulating Washer, said insulating washer and said wire being free to rotate relatively to said core; a metallic washer surrounding said tubular portion and adapted to bear against said abutment, said tubular portion being free to rotate relatively to said washer; a spring interposed between the back of said recessed portion of the core and said metallic washer and urging said metallic washer rearwardly and said cup-shaped contact member against a contact upon a plug received in the front end of the shell, said cup-shaped contact member having a roughened periphery engaging said other contact, whereby friction between the contacts is increased and the effects of vibration are reduced; and a handle locked in a slot in said core and projecting through a cam slot formed through said shell, said cam slot being shaped to locate the handle in a circuit opening position and permitting the handle to have a circuit closing portion.

2. In a circuit continuing device, the combination with a shell; of a metallic core reciprocable therein and having an axially recessed portion at one end and a tubular portion connected to said axially recessed portion and extending rearwardly of the core; an insulating washer in said recessed portion; fingers stuck from the core and loosely retaining the insulating washer in the recess; a contact member carried concentrically by said insulating washer, said Washer being disposed between said contact member and said core; and an insulated wire passing through said tubular portion and secured to said contact member, whereby said wire and said contact member are insulated from said core and are revoluble with respect to the core while being reciprocable therewith.

3. The structure of claim 2 wherein the insulated wire is provided with metallic armor and said armor is continued into said tubular portion of the core.

4. In a circuit continuing device, the combination with a shell having a bore formed at its forward end to receive a contact carrying plug and having an abutment at its other end; of a core rotatable and reciprocable in the bore of the shell, said core having a recessed conical portion at its forward end; an insulated contact member rotatively carried by the recessed portion of the core; a spring interposed between said core and abutment and urging said contact member against a contact upon a plug received in the frontend of the shell, the core having a skirt portion in close proximity to the surface of the bore of the shell; and a handle locked to said skirt portion of the core and projecting through a cam slot formed through said shell said slot being shaped to locate the handle in a circuit opening position and permitting the handle to have a circuit closing position.

5. In a circuit continuing device,'the combina tion with a shell formed at its forward end to receive a contact carrying plug and having an abutment at its other end; a core having a skirt portion in close proximity to the surface of the bore of the shell and having a tubular portion extending rearwardly of the shell; an insulated current carrying member passing through said tubular portion and secured to said core, said current carrying member being free to rotate relatively to said core; a washer surrounding said tubular portion and adapted to bear against said abutment; a spring interposed between the core and washer and urging said current carrying member against a contact upon a plug received in thefront end of the shell; and a handle locked in a slot in said core and projecting through a cam slot formed through said shell, said cam slot being shaped to locate the handle in a circuit opening position and permitting the handle to have a circuit closing position.

6. In a circuit continuing device, the combination of a cylindrical metal shell having a wall split longitudinally to provide a free segmental portion adapted to act as a spring, a metallic washer in the bore of said shell, said washer having peripheral spring fingers engaging the wall of the bore and spacing the body of the washer from the wall, whereby the washer accommodates itself to expansion and contraction of the shell, and an insulated current conductor passing loosely through the center of the washer.

7. In a circuit continuing device, the combination with an axially recessed metallic member having a hollow conical portion at its forward end and a tubular portion connected to said conical portion and extending rearwardly of the member; an insulating washer carried in the recess formed by the hollow conical portion, said washer being of a diameter approximately the maximum diameter of the conical portion; a contact member carried concentrically by the,insulating washer; and an insulated wire passing through the tubular portion and secured to the/ contact member, whereby the wire and contact--- member are insulated from the member.

HARRY A. DOUGLAS. 

